http://www.perlmonks.org?node_id=1206

File::Find

See the current Perl documentation for File::Find.

Here is our local, out-dated (pre-5.6) version:

find - traverse a file tree

finddepth - traverse a directory structure depth-first

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    use File::Find;
    find(\&wanted, '/foo','/bar');
    sub wanted { ... }

    use File::Find;
    finddepth(\&wanted, '/foo','/bar');
    sub wanted { ... }

The first argument to find() is either a hash reference describing the operations to be performed for each file, or a code reference. If it is a hash reference, then the value for the key wanted should be a code reference. This code reference is called the wanted() function below.

Currently the only other supported key for the above hash is bydepth, in presense of which the walk over directories is performed depth-first. Entry point finddepth() is a shortcut for specifying { bydepth = 1}> in the first argument of find().

The wanted() function does whatever verifications you want. $File::Find::dir contains the current directory name, and $_ the current filename within that directory. $File::Find::name contains "$File::Find::dir/$_". You are chdir()'d to $File::Find::dir when the function is called. The function may set $File::Find::prune to prune the tree.

File::Find assumes that you don't alter the $_ variable. If you do then make sure you return it to its original value before exiting your function.

This library is useful for the find2perl tool, which when fed,

    find2perl / -name .nfs\* -mtime +7 \
        -exec rm -f {} \; -o -fstype nfs -prune

produces something like:

    sub wanted {
        /^\.nfs.*$/ &&
        (($dev,$ino,$mode,$nlink,$uid,$gid) = lstat($_)) &&
        int(-M _) > 7 &&
        unlink($_)
        ||
        ($nlink || (($dev,$ino,$mode,$nlink,$uid,$gid) = lstat($_))) &&
        $dev < 0 &&
        ($File::Find::prune = 1);
    }

Set the variable $File::Find::dont_use_nlink if you're using AFS, since AFS cheats.

finddepth is just like find, except that it does a depth-first search.

Here's another interesting wanted function. It will find all symlinks that don't resolve:

    sub wanted {
        -l && !-e && print "bogus link: $File::Find::name\n";
    }

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BUGS

There is no way to make find or finddepth follow symlinks.

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